code: def test_init(self):
      train_set = SequentialDataset.from_usit(self.sequential_data)
  
      self.assertEqual(train_set.num_sessions, 16)
      self.assertEqual(train_set.max_session_size, 6)
      self.assertEqual(train_set.min_session_size, 2)
  
      self.assertEqual(train_set.num_users, 5)
      self.assertEqual(train_set.num_items, 9)
  
      self.assertEqual(train_set.uid_map["1"], 0)
      self.assertEqual(train_set.sid_map["1"], 0)
      self.assertEqual(train_set.iid_map["1"], 0)
  
      self.assertSetEqual(
          set(train_set.user_ids),
          set(["1", "2", "3", "4", "5"]),
      )
  
      self.assertSetEqual(
          set(train_set.item_ids),
          set(["1", "2", "3", "4", "5", "6", "7", "8", "9"]),
      )
  
imports: import unittest
  import numpy
  import numpy.testing
  from cornac.data import BasketDataset, Dataset, SequentialDataset, Reader
label_desc: Use image node_id 2 for calling the TestSequentialDataset obj's underlying member method code with example usage: obj.test_init() without return types